Tension ring for compressor vane

ABSTRACT

A hollow cylindrical body and two end walls define a compression chamber in which a rotor is disposed. Hubs are formed on the outer sides of the end walls for receiving a pair of tension rings. A vane is disposed in a radial opening formed in the body and engages the rotor for dividing the chamber into high and low pressure sides. The vane is held in engagement with the rotor by a pair of coil springs disposed between the outer end of the vane and the tension rings.

Unite States 'atent 1191 Bellmer 1 elb.5, 1974 TENSION RING FOR'COMPRESSOR VANE [75] Inventor: Thomas J. Bellmer, Stanhope, NJ.

[73] Assignee: Fedders Corporation, Edison, NJ.

8/1936 Klemm,.lr. 137/3842 12/1969 Wurzel 267/161 Primary Examiner-James B. Marbert Attorney, Agent, or Firm-Ryder, McAuloy, Fields, Fisher & Goldstein.

[5 7 ABSTRACT A hollow cylindrical body and two end walls define a compression chamber in which a rotor is disposed. Hubs are formed on the outer sides of the end walls for receiving a pair of tension rings. A vane is disposed in a radial opening formed in the body and engages the rotor for dividing the chamber into high and low [56] References Cited pressure sides. The vane is held in engagement with UNI STATES PATENTS the rotor by a pair of coil springs disposed between 3,444,790 5/1969 Rumsey 92/121 the Outer end of the vane and the tension rings 10 Claims, 4 Drawing Figures l I l 1'" TENSION RING FOR COMPRESSOR VANE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to rotary compressors and more particularly to means for maintaining the vane of a rotary compressor in engagement with the rotor.

- 2. Description of the Prior Art A typical prior art rotary compressor comprises a hollow cylindrical body, end walls to define a cylindrical compression chamber, a rotor eccentrically mounted within the cylindrical compression chamber and a slidable vane disposed within a radial slot formed in the wall of the cylindrical body. The vane engages the surface of the rotor, thereby dividing the cylindrical compression chamber into high and low pressure sides.

Spring means is utilized to urge the vane into sealing engagement with the rotor surface.

Referring to FIG. 1, there is shown a typical prior art rotary compressor including a cast metal body and end walls 12 having hubs 14. A vane 16 is disposed within a radial slot formed in the body for engagement with the surface of a rotor, which is disposed within the compressor. Vane arms 18 are connected to vane 16 at the outer end thereof for receiving first ends 21 of coil springs 20. Pins 22 are mounted in reinforced portions 24 of end walls 12 and are adapted to receive the second ends 23 of springs 20. Springs exert a force on vane 16 to maintain the vane in engagement with the surface of the rotor.

In the prior art, the use of pins as shown in FIG. I greatly increased the cost of components and the assembly cost of the compressor. When the pins were molded as an integral part of the end walls, the mold cost was greatly increased, which resulted in a high cost compressor. Alternately, when the pins were screwed or pressed into holes in the ends walls, the holes had to be formed by molding or drilling. Again, this resulted in increased assembly costs. The pins could not be welded to the end walls because the walls were cast components.

It was essential for the pins to be securely anchored into the end walls. Thus, a reinforced portion 24 of greater thickness was required which resulted in the springs being positioned a considerable distance from the cylindrical body thereby increasing the overall width of the compressor. Thus, the prior art rotary compressors had high component costs, high assembly costs and an excesive width.

SUMMARY OF THE INVENTION The present invention comtemplates a rotary compressor, including a hollow cylindrical body, end walls having outwardly extending hubs and a rotor disposed within the cylindrical body. A vane is slidably disposed in a radial slot formed in the cylindrical body for en gagement with the surface of the rotor to divide the compressor into a high and low pressure side.

Vane arms similar to those used in the prior art are attached to the outer end of the vane for connection with the first ends of a pair of coil springs. The second ends of the coil springs are connected to a pair of tension rings that are disposed about the hubs. The tension rings are preferably stamped from a sheet material and having inwardly extending tabs for engaging the hubs and securing the tension rings in place. Feet are formed on the rings and extend inwardly or outwardly for engagement with the end walls so that the rings are spaced a predetermined distance from the end walls and the tension springs do not contact the end walls.

One objective of the present invention is to provide a rotary compressor having a smaller size than those previously provided.

Another objective of the present invention is to provide a rotary compressor that is less expensive than those heretofore provided.

Another objective of the present invention is to provide a rotary compressor that may be more easily assembled than those heretofore provided.

The foregoing objectives and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawing, wherein two embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawing is for illustrative purposes only and is not to be considered as defining the limits of the invention.

DESCRIPTION OF THE DRAWNG FIG. I is a front view of a typical prior art rotary compressor.

FIG. 2 is a front view of a rotary compressor constructed in accordance with the present invention.

FIG. 3 is a plan view of a tension ring utilized in the present invention.

FIG. 4 is a plan view of a second embodiment of a tension ring utilized in the present invention.

DESCRIPTION OF THE lNVENTION Referring to FIG. 2, there is shown a rotary compressor contructed in accordance with the present invention. The compressor has a cast cylindrical body 26 having a hollow interior. Two end walls 26, also formed by casting, have'outwardly extending hubs 30. End walls 28 and body 26 define an interior compression chamber in which is disposed a rotor eccentrically attached to one end of a shaft 32. A vane 34 is slidably disposed within a radial slot formed in body 26 for engagement with the surface of the rotor in a manner well known in the art.

Vane arms 36 are connected to the outermost end of vane 34 and have depressions 38 formed therein for engaging the first end of coil springs 42. Springs 42 have second ends 44 engaging tension rings 46.

Tension rings 46 are disposed about hubs 30 and are spaced from end walls 28, the spacing being such that springs 42 do not contact the outer surface of end walls 28. In the preferred embodiment, tension rings 46 have inwardly extending feet 48 for engagementwith the outer surfaces of end walls 28. The feet function to space the tension ring a predetermined distance from the end walls.

The rings have inwardly extending tabs 50, most clearly shown in FIGS. 3 and 4, which engage the hubs to secure the tension rings in position on the hubs. Tabs 50 extend inwardly of tension rings 46 so that their ends are tangential to a circle, having a diameter slightly less than the diameter of hubs 30. To facilitate the placing of rings 46 around hubs 30, tabs 50 are bent slightly in an outwardly direction away from endwalls 28 Thus, when the rings are slid in place over the hubs,

tabs 50 engage the hubs preventing movement of the rings in a direction away from end walls 28.

Referring to FIG. 3, a notch 52 is formed in ring 46 for receiving the second end 44 of spring 42. Referring to FIG. 4, there is shownanother embodiment wherein a hole 54 is formed in ring 46 for receiving end 44 of spring 42.

In the ring embodiment shown in FIG. 4, the tabs 50 are disposed equally around the ring. The tabs flex and bend as the ring is inserted over a hub and the amount that each tab bends is not necessarily equal. Therefore, the relative position of the ring to the center axis of the compressor is not known, but this is not a critical consideration in all cases.

If the spring tension is critical and it is desirable that ends 44 of the springs be positioned at a known distance from the axis of the compressor, the ring embodiment shown in FIG. 3 is preferred. In FIG. 3, tabs 50 are formed on the notch side of the ring so that the ring itself, rather than the tabs, engages the hub on the side opposite the springs. The side of the ring opposite notch 52 may be formed with a smooth, curved inner surface for engagement with hub 30 or with a straight surface 51, as shown in FIG. 3 for engaging the hub. Thus, the ring embodiment shown in FIG. 3 assures that the notch and spring ends are at a specified distance from the center axis of the compressor.

While the tension rings may take many forms, they are preferably stamped from sheet metal after which tabs 50 are bent slightly in one direction and feet 48 are bent in an opposite direction. Springs 42 may be attached to rings 46 prior to installation of the rings on the hubs. The rings are then merely slid onto the hubs from opposite sides of the compressor, thereby greatly simplifying the assembly procedure. Feet 48 properly space the rings from end walls 28 so that the springs are clear of the end walls and are free to move without interference.

It is to be understood that other forms of feet could be used to space the rings from the end walls. The feet could be formed on the inside edge of ring 46, similar to tabs 50. Separately formed feet could easily be attached to the rings in any well known manner. Another method of spacing the rings from the end walls would be by the use of raised portions molded integrally with the end walls in a manner similar to the formation of the reinforced portions of the prior art. However, these raised portions would be positioned around the end wall at positions other than that of the springs so that the overall width of the compressor may be reduced.

The present invention greatly simplifies the casting of the end walls by the elimination of the reinforced portion and the need for a pin. The assembly procedure is simplified in that the requirement for pin holes is eliminated and the tension rings need only be slid over the ends of the hubs during assembly. The overall width of the compressor is reduced, because the springs may be positioned closer to the end walls. Thus, the present invention provides a smaller and less expensive rotary compressor than those heretofore provided.

What is claimed is:

1. In a rotary compressor comprising a hollow cylindrical body, a pair of end walls, at least one of which has a hub extending therefrom, the end walls and cylindrical body defining a cylinder, a rotor eccentrically rotatable within said cylinder, a radial slot formed in the cylindrical body, a vane slidably disposed in said slot for engagement with the rotor, and means for maintaining said vane in engagement with said rotor, said means comprising:

a vane arm attached to the outermost end of the vane;

a tension ring disposed about said hub and positioned adjacent the end wall, said ring including members disposed on one side thereof for engagement with said end wall, whereby the tension ring is spaced a predetermined distance from said end wall; and

a tension spring disposed between said vane arm and said tension ring for exerting a force on said vane, thereby maintaining said vane in engagement with the surface of said rotor.

2. A rotary compressor as described in claim 1, additionally comprising:

a second hub extending from the other end wall;

a second vane arm attached to the end of the vane and extending in a direction opposite the other arm;

a second tension ring disposed about the second hub;

and

a tension spring disposed between the second vane arm and the second tension ring.

3. A rotary compressor as described in claim 1, wherein the tension spring is a coil spring maintained under tension.

4. A rotary compressor as described in claim 1 wherein the tension ring is formed of a flat sheet material and has a notch formed therein for receiving one end of the tension spring.

5. A rotary compressor as described in claim I, wherein the tension ring is formed ofa flat sheet material and has a hole formed therein for receiving one end of the tension spring.

6. A rotary compressor as described in claim 1, wherein the tension ring additionally includes means for retaining the ring on said hub.

7. A rotary compressor as described in claim 1, wherein the tension ring is formed of a flat sheet material and additionally includes inwardly extending tabs that engage the hub when the ring is disposed around the hub, thereby preventing removal of the ring from the hub.

8. A rotary compressor as described in claim 1, additionally comprising means for spacing said tension ring at a predetermined distance from said end wall.

9. A rotary compressor as described in claim 1, wherein the tension ring has a rigid portion adapted to engage the hub at a position opposite the vane.

10. Arotary compressor as described in claim 1, wherein the tension spring is a coil spring maintained under tension and the tension ring is formed of a flat sheet material and additionally includes:

a notch for receiving one end of the tension spring;

a rigid portion disposed opposite said notch for engagement with the hub; v

inwardly extending tabs for engaging the hub and locking said ring in position on said hub; and

inwardly disposed feet for engaging the end wall so that the ring is spaced from the end wall at a predetermined distance. 

1. In a rotary compressor comprising a hollow cylindrical body, a pair of end walls, at least one of which has a hub extending therefrom, the end walls and cylindrical body defining a cylinder, a rotor eccentrically rotatable within said cylinder, a radial slot formed in the cylindrical body, a vane slidably disposed in said slot for engagement with the rotor, and means for maintaining said vane in engagement with said rotor, said means comprising: a vane arm attached to the outermost end of the vane; a tension ring disposed about said hub and positioned adjacent the end wall, said ring including members disposed on one side thereof for engagement with said end wall, whereby the tension ring is spaced a predetermined distance from said end wall; and a tension spring disposed between said vane arm and said tension ring for exerting a force on said vane, thereby maintaining said vane in engagement with the surface of said rotor.
 2. A rotary compressor as described in claim 1, additionally comprising: a second hub extending from the other end wall; a second vane arm attached to the end of the vane and extending in a direction opposite the other arm; a second tension ring disposed about the second hub; and a tension spring disposed between the second vane arm and the second tension ring.
 3. A rotary compressor as described in claim 1, wherein thE tension spring is a coil spring maintained under tension.
 4. A rotary compressor as described in claim 1 wherein the tension ring is formed of a flat sheet material and has a notch formed therein for receiving one end of the tension spring.
 5. A rotary compressor as described in claim 1, wherein the tension ring is formed of a flat sheet material and has a hole formed therein for receiving one end of the tension spring.
 6. A rotary compressor as described in claim 1, wherein the tension ring additionally includes means for retaining the ring on said hub.
 7. A rotary compressor as described in claim 1, wherein the tension ring is formed of a flat sheet material and additionally includes inwardly extending tabs that engage the hub when the ring is disposed around the hub, thereby preventing removal of the ring from the hub.
 8. A rotary compressor as described in claim 1, additionally comprising means for spacing said tension ring at a predetermined distance from said end wall.
 9. A rotary compressor as described in claim 1, wherein the tension ring has a rigid portion adapted to engage the hub at a position opposite the vane.
 10. A rotary compressor as described in claim 1, wherein the tension spring is a coil spring maintained under tension and the tension ring is formed of a flat sheet material and additionally includes: a notch for receiving one end of the tension spring; a rigid portion disposed opposite said notch for engagement with the hub; inwardly extending tabs for engaging the hub and locking said ring in position on said hub; and inwardly disposed feet for engaging the end wall so that the ring is spaced from the end wall at a predetermined distance. 